Astrobiology Science Conference 2010 (2010) 5095.pdf SUGARS AS THE SOURCE OF ENERGIZED CARBON FOR ABIOGENESIS. A. L. Weber, SETI Institute, NASA Ames Research Center, Mail Stop 239-4, Moffett Field, CA, 94035-1000, [email protected] Abstract: As shown in Figure 1, abiogenesis has sev- eral requirements: (A) a source of organic substrates and chemical energy that drives the synthesis of (B) useful small molecules (ammonia, monomers, metabo- lites, energy molecules), and (C) a second synthetic processs that yields large replicating and catalytic polymers that control (D) the growth and maintenance of a primitive protocell. Furthermore, the required chemical energy must be sustained and effectively coupled to individual reactions to drive biosynthesis at a rate that counters chemical degradation. Energy coupling would have been especially difficult during the origin of life before the development of powerful enzyme catalysts with 3-D active sites. To solve this energy coupling problem we have investigated abio- genesis using sugar substrates whose energized carbon groups drive spontaneous synthetic self-transformation reactions that yield: biometabolites, catalytic mole- cules, energy-rich thioesters, amino acids, plausible alternative nucleobases and cell-like microstructures [1-8]. Recently, we demonstrated that sugars drive the synthesis of ammonia from nitrite [9]. The ability of sugars to drive ammonia synthesis provides a way to generate ammonia at microscopic sites of sugar-based origins processes, thereby eliminating the need for a planet-wide source of photochemically unstable am- monia. Figure 1. Major Synthetic Processes of Abiogenesis. [1] Weber A. L. (1998) Orig. Life Evol. Biosph., 28, 259-270. [2] Weber A. L. (2001) Orig. Life Evol. Bi- osph., 31, 71-86. [3] Weber A. L. (2002) Orig. Life Evol. Biosph., 32, 333-357. [4] Weber A. L. (2004) Orig. Life Evol. Biosph., 34, 473-495. [5] Weber A. L. (2005) Orig. Life Evol. Biosph., 35, 523-536. [6] We- ber A.L. and Pizzarello S. (2006) Proc. Nat. Acad. Sci. USA, 103, 12713-12717. [7] Weber A. L. (2007) Orig. Life Evol. Biosph., 37, 105-111. [8] Weber A. L. (2008) Orig. Life Evol. Biosph., 38, 279-292. [9] We- ber A. L. (2009) Orig. Life Evol. Biosph., in press. .